1. Field of the Invention
The present invention relates to a screw apparatus for supplying a reinforcing fiber-containing molten resin and a method for supplying a reinforcing fiber-containing molten resin by means the apparatus.
2. Related Background Art
As conventional methods for injection molding of a fiber-reinforced resin, methods in which reinforcing fibers are introduced into molten resin in a screw injection machine has been proposed (Japanese Patent Laid-Open (Kokai) Nos. 153714/1990 and 286617/1992).
However, according to the above conventional methods, the reinforcing fibers which can be fed uniformly have limit in their length and length of the reinforcing fibers after molded is still insufficient. Moreover, the state of dispersion of the reinforcing fibers in the resin is also insufficient to cause fluctuation in filling of the reinforcing fibers in the articles.
As another conventional method, a method in which fibers and a resin material (non-molten state) are respectively and directly introduced into an injection machine is known (Japanese Patent Laid-Open (Kokai) No. 8278/1994).
However, according to this conventional method, it is also difficult to keep the fibers in a long size, and the fiber length can be kept only at about 400-500 .mu.m which is still insufficient.